GILLEN, C.M.*; GAO, Y.; WYLDE, M.R.; WHEATLY, M.G.; Kenyon College, Gambier, OH; Wright State University, Dayton, OH; Kenyon College, Gambier, OH; Wright State University, Dayton, OH: Cloning and expression pattern of Procambarus clarkii elongation factor 1&gamma

Elongation factor 1 is a multisubunit protein that is part of the protein synthesis apparatus in eukaryotes. We have cloned a portion of the elongation factor 1 gamma (EF-1&gamma) gene from tail muscle of the freshwater crayfish Procambarus clarkii by reverse transcriptase polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE). The cloned nucleotide sequence has approximately 65% homology to EF-1&gamma genes from Locusta migratoria and Drosophila melanogaster. We assessed expression of crayfish EF-1&gamma by real time PCR, using the relative quantification method and 18s ribosomal RNA as an internal calibrator. EF-1&gamma expression was lowest in gill, tail muscle, and hepatopancreas, and was highest in the antennal gland (5.7 fold above hepatopancreas) and cardiac muscle (7.8 fold above hepatopancreas). In epithelial tissues, EF-1&gamma expression decreased during pre and post molt. EF-1&gamma expression in the antennal gland was 2.9 fold higher during intermolt compared to premolt while expression in the hepatopancreas was 3.5 fold higher during intermolt compared to premolt. In contrast, EF-1&gamma expression increased in muscle tissues during pre and post molt. In tail muscle, EF-1&gamma expression was 4.4 fold higher in premolt and 11.9 higher in postmolt compared to intermolt. Expression of EF-1&gamma in cardiac muscle was 1.8 higher in premolt and 2.2 higher in postmolt compared to intermolt. These results show that EF-1&gamma is differentially regulated in muscle tissues compared to epithelial tissues during the molting cycle in crayfish. This work supported by NSF IBN 0076035 to M.G.W.